// Scintilla source code edit control
/** @file KeyWords.cxx
 ** Colourise for particular languages.
 **/
// Copyright 1998-2002 by Neil Hodgson <neilh@scintilla.org>
// The License.txt file describes the conditions under which this software may be distributed.

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include <stdarg.h>

#include "WordList.h"

#ifdef SCI_NAMESPACE
using namespace Scintilla;
#endif

/**
 * Creates an array that points into each word in the string and puts \0 terminators
 * after each word.
 */
static char **ArrayFromWordList(char *wordlist, int *len, bool onlyLineEnds = false) {
    int prev = '\n';
    int words = 0;
    // For rapid determination of whether a character is a separator, build
    // a look up table.
    bool wordSeparator[256];
    for (int i=0; i<256; i++) {
        wordSeparator[i] = false;
    }
    wordSeparator['\r'] = true;
    wordSeparator['\n'] = true;
    if (!onlyLineEnds) {
        wordSeparator[' '] = true;
        wordSeparator['\t'] = true;
    }
    for (int j = 0; wordlist[j]; j++) {
        int curr = static_cast<unsigned char>(wordlist[j]);
        if (!wordSeparator[curr] && wordSeparator[prev])
            words++;
        prev = curr;
    }
    char **keywords = new char *[words + 1];
    if (keywords) {
        words = 0;
        prev = '\0';
        size_t slen = strlen(wordlist);
        for (size_t k = 0; k < slen; k++) {
            if (!wordSeparator[static_cast<unsigned char>(wordlist[k])]) {
                if (!prev) {
                    keywords[words] = &wordlist[k];
                    words++;
                }
            } else {
                wordlist[k] = '\0';
            }
            prev = wordlist[k];
        }
        keywords[words] = &wordlist[slen];
        *len = words;
    } else {
        *len = 0;
    }
    return keywords;
}

bool WordList::operator!=(const WordList &other) const {
    if (len != other.len)
        return true;
    for (int i=0; i<len; i++) {
        if (strcmp(words[i], other.words[i]) != 0)
            return true;
    }
    return false;
}

void WordList::Clear() {
    if (words) {
        delete []list;
        delete []words;
    }
    words = 0;
    list = 0;
    len = 0;
}

extern "C" int cmpString(const void *a1, const void *a2) {
    // Can't work out the correct incantation to use modern casts here
    return strcmp(*(char **)(a1), *(char **)(a2));
}

static void SortWordList(char **words, unsigned int len) {
    qsort(reinterpret_cast<void *>(words), len, sizeof(*words),
          cmpString);
}

void WordList::Set(const char *s) {
    Clear();
    list = new char[strlen(s) + 1];
    strcpy(list, s);
    words = ArrayFromWordList(list, &len, onlyLineEnds);
    SortWordList(words, len);
    for (unsigned int k = 0; k < (sizeof(starts) / sizeof(starts[0])); k++)
        starts[k] = -1;
    for (int l = len - 1; l >= 0; l--) {
        unsigned char indexChar = words[l][0];
        starts[indexChar] = l;
    }
}

/** Check whether a string is in the list.
 * List elements are either exact matches or prefixes.
 * Prefix elements start with '^' and match all strings that start with the rest of the element
 * so '^GTK_' matches 'GTK_X', 'GTK_MAJOR_VERSION', and 'GTK_'.
 */
bool WordList::InList(const char *s) const {
    if (0 == words)
        return false;
    unsigned char firstChar = s[0];
    int j = starts[firstChar];
    if (j >= 0) {
        while ((unsigned char)words[j][0] == firstChar) {
            if (s[1] == words[j][1]) {
                const char *a = words[j] + 1;
                const char *b = s + 1;
                while (*a && *a == *b) {
                    a++;
                    b++;
                }
                if (!*a && !*b)
                    return true;
            }
            j++;
        }
    }
    j = starts['^'];
    if (j >= 0) {
        while (words[j][0] == '^') {
            const char *a = words[j] + 1;
            const char *b = s;
            while (*a && *a == *b) {
                a++;
                b++;
            }
            if (!*a)
                return true;
            j++;
        }
    }
    return false;
}

/** similar to InList, but word s can be a substring of keyword.
 * eg. the keyword define is defined as def~ine. This means the word must start
 * with def to be a keyword, but also defi, defin and define are valid.
 * The marker is ~ in this case.
 */
bool WordList::InListAbbreviated(const char *s, const char marker) const {
    if (0 == words)
        return false;
    unsigned char firstChar = s[0];
    int j = starts[firstChar];
    if (j >= 0) {
        while (words[j][0] == firstChar) {
            bool isSubword = false;
            int start = 1;
            if (words[j][1] == marker) {
                isSubword = true;
                start++;
            }
            if (s[1] == words[j][start]) {
                const char *a = words[j] + start;
                const char *b = s + 1;
                while (*a && *a == *b) {
                    a++;
                    if (*a == marker) {
                        isSubword = true;
                        a++;
                    }
                    b++;
                }
                if ((!*a || isSubword) && !*b)
                    return true;
            }
            j++;
        }
    }
    j = starts['^'];
    if (j >= 0) {
        while (words[j][0] == '^') {
            const char *a = words[j] + 1;
            const char *b = s;
            while (*a && *a == *b) {
                a++;
                b++;
            }
            if (!*a)
                return true;
            j++;
        }
    }
    return false;
}
